At a time when there is an increasing demand for demographic information about hearing-impaired senior citizens, such research on older persons with hearing losses is relatively scarce. Demand for this information will grow in the future as the size of the elderly population increases. The long-term objective of this three-year project is to improve the quality of national information available about the role of demographic factors in the process of hearing decline in old age. The proposed research will increase knowledge of the dynamic interaction of aging and hearing loss by attempting to isolate factors related to pathology from those involving normal aging. Within the context of social and cultural variability, this project will emphasize the natural age-related trajectory of hearing loss. In so doing, understanding of the interrelation of hearing loss in old age with processes that occur at earlier ages will be augmented. The study will thus serve as a basis for action for those who provide health and other services for elderly persons who are hearing-impaired or at risk for hearing impairment. The specific aims are: 1) to determine the most appropriate statistical models for the interaction of aging and hearing loss and of the influence of demographic factors on this interation, 2) to discover the degree to which socio-economic status influences the risk of hearing loss, its age at onset and the rate of hearing decline, 3) to identify whether the process of age-related hearing loss exists independently of identifiable diseases and 4) to increase the applicability of data presently available on hearing impairments. Demographic methodology will be employed to analyze test results and medical histories from the first Health and Nutrition Examination Survey, 1971-75, and of the responses to the 1971 and 1977 supplements to the National Health Interview Survey. These data sources have not been used to thsir fullest potential and comparable data are not likely to be collected in the near future. Thus, these data sources must be analyzed while the information contained therein is still relevant.